Fluid pump with resilient pumping membrane

ABSTRACT

Disclosed herein is a fluid pump comprising a housing having therein a pocket, a pumping membrane of resilient material and including therein a pumping cavity located in the housing pocket, together with one-way fluid inlet and outlet valves connected to the opposite ends of the pumping membrane and means for periodically squeezing the pumping cavity within the pocket so as to reduce the volume of the cavity and thereafter permitting expansion of the cavity to thereby induce fluid flow from the membrane through the outlet valve in response to squeezing of the cavity and to induce fluid into the cavity through the inlet valve in response to expansion of the cavity.

United States Patent 11 1 1111 3,881,846 Kashmerick 1 May 6, 1975 1FLUID PUMP WITH RESILIENT PUMPING 1,503,660 2/1970 Germany 418/48MEMBRANE 597,046 1/1948 United Kingdom 417/478 FOREIGN PATENTS ORAPPLICATIONS France 417/475 Primary Examiner-William L.. Freeh AssistantExaminer-Richard E. Gluck Attorney, Agent, or FirmMichael, Best &Friedrich [57] ABSTRACT Disclosed herein is a fluid pump comprising ahousing having therein a pocket, a pumping membrane of resilientmaterial and including therein a pumping cavity located in the housingpocket, together with one-way fluid inlet and outlet valves connected tothe opposite ends of the pumping membrane and means for periodicallysqueezing the pumping cavity within the pocket so as to reduce thevolume of the cavity and thereafter permitting expansion of the cavityto thereby induce fluid flow from the membrane through the outlet valvein response to squeezing of the cavity and to induce fluid into thecavity through the inlet valve in response to expansion of the cavity,

4 Claims, 4 Drawing Figures FLUID PUMP WITH RESILIENT PUMPING MEMBRANEBACKGROUND OF THE INVENTION The invention relates generally to pumps andmore particularly to pumps including a resilient membrane containing thefluid being pumped.

Most prior pumps include rubbing contact between the surfaces whichcontact the fluid being pumped and are accordingly subject to high wearand heat genera tion when operating dry and have a low tolerability forpumping abrasive fluids i.e., for instance, sandy fluids. In addition,such pumps provide poor suction characteristics especially when startedin a dry condition.

SUMMARY OF THE INVENTION The invention provides a fluid pump including ahousing having therein a pocket, a pumping membrane or member ofresilient material located in the housing pocket and including therein apumping cavity, a oneway fluid inlet valve connected to one end of thepumping cavity, a one-way outlet fluid valve connected to the other endof the pumping cavity, and means for periodically squeezing the membranewithin the pocket so as to reduce the volume of the cavity andthereafter permitting expansion of the cavity to thereby induce fluidoutflow from the cavity through the outlet valve in response tosqueezing of the membrane and to induce fluid inflow into the cavitythrough the inlet valve in response to expansion of the cavity.

In further accordance with the invention, the housing includes aplurality of inwardly open pockets arranged in a circular array, themembrane includes a like plurality of cavities located in the pockets,and a series of inlet and outlet valves are provided, one inlet and oneoutlet valve for each cavity. In addition, the means for periodicallysqueezing the membrane and thereafter permitting expansion of thecavities comprises a drive shaft extending through the housing inconcentric relation to the array of pockets, a cylindrical cam elementmounted on the drive shaft in excentric relation thereto and for commonrotation therewith, a bearing located on the outer surface of the camelement, and a hollow cylindrical member including an outer surfacebonded to the membrane and an inner surface in engagement with thebearing.

One of the principal features of the invention is the provision of afluid pump in which there is no rubbing between fluid contactingcomponents.

Another of the principal features of the invention is the provision of afluid pump having dry suction ability.

Still another of the principal features of the invention is theprovision of a fluid pump which provides pumping action withoutencountering high wear and heat generation when started dry and withoutexperiencing high wear when pumping abrasive liquids.

Still another of the principal features of the invention is theprovision of a fluid pump including a pumping membrane which isconstructed of resilient material, such as rubber. and which includes aplurality of elongated cavities extending between one-way inlet andoutlet valves and which are periodically squeezed in the directiontransverse to the elongation of the cavities and then released to effectflow through the cavities from the inlet valves and out the outletvalves.

Other features and advantages of the invention will become known byreference to the following drawings,

FIG. 1 is a diametrical sectional view of a fluid pump in accordancewith the invention.

FIG. 2 is a sectional view taken along line 22 of FIG. 1.

FIG. 3 is a sectional view taken along line 3-3 of FIG. I.

FIG. 4 is a sectional view taken-along line 4-4 of FIG. 1.

Before explaining the invention in detail, it is to be understood thatthe invention is not limited in its application to the details ofconstruction and the arrangements of the components set forth in thefollowing description or illustrated in the drawings. The invention iscapable of other embodiments and of being practiced and carried out invarious ways. Also, it is to be understood that the phraseology andterminology employed herein is for the purposes of description andshould not be regarded as limiting.

GENERAL DESCRIPTION Shown in the drawings is a fluid pump 11 which em'bodies the invention, which includes a housing 13 having therein apocket 15, a pumping membrane 17 of resilient material having a pumpingcavity 19 located in the housing pocket 15, a one-way fluid inlet valve2l connected to the pumping cavity 19, a one-way fluid outlet valve 23connected to pumping cavity 19, and

means for periodically squeezing the membrane within the pocket 15 toreduce the volume of the cavity 19 and thereafter permitting expansionof the cavity 19 so as to thereby induce fluid outflow from the cavity19 through the outlet valve 23 in response to the squeezing of themembrane and to induce fluid flow into the eavity 19 through the inletvalve 21 in response to expansion of the cavity 19.

More particularly, in the illustrated construction, the housing 13 isformed of two sections or members 29 and 31 and includes a generallycylindrical outer sur-' face 33 and a central part or portion 35 with aninner surface defining a series of elongated, radially inwardly openpockets 15 arranged in a. generally evenly spaced, circular array. Anynumber and form'of pockets can be employed. In the illustratedconstruction, six generally which are preferably circular and which arealigned with and communicate with the pockets 15.

As will be more fully appreciated hereinafter, the end of the housing 13shown to the: left in FIG. 1 is provided with a housing end member orcover 41 including an axially inwardly opening, fluid outlet manifoldpassage 43 communicating with the adjacent series of openings 37 andwith an outlet (not shown) adapted to communicate with exterior piping.

At its other or right end as shown in FIG. 1, the housing 13 is providedwith a valve retainer 51 which includes a series of counterboredopenings 53 in alignment with and communicating with the adjacent seriesof openings 37 in the adjacent housing end, together with an axiallyoutwardly open, common fluid inlet passage 55 which communicates withthe openings 53 and has an inlet (not shown) adapted to be connected toa source of fluid to be pumped. Covering the axially outwardly openinlet passage 55 is a housing end member or cover 57.

' The housing sections 29 and 31, valve retainer 51,

' 'wardly from the cylindrical inner portion 61 and which each containan elongated axially extending pumping cavity 19. At each end of themembrane 17, the cavities 19are open and there is provided (see FIG. 1)a lip or flange 65 which, at the end of the housing shown to the I leftin FIG. 1, is retained between the cover 41 and the housing section 29,and which, at the right end of the housing 13, isretained between thehousing section 31 and the valve retainer 51. Accordingly, the pumpingmembrane 17 is generally fixed relative to the housing 13. i

' JAs already indicated, the membrane 17 is formed of 'resilientmaterial and each cavity 19 is inherently biased to a maximum volumesuch that the associated @porjection 63 of volume is greater than thevolume of the'associated pocket 15. Of course, the number of cavities 19corresponds to the number of housing pockets 15 and there is included aseparate inlet and outlet -valve for each cavity.

Preferably, one of the series of outlet valves 23 and i 1 the seriesofinlet valves 21 is formed integrally with the -pumping membrane 17 andthe other series is formed as one piece member 71 which is adapted tointerflt with the adjacent end of the pumping membrane 17. In

. .the illustrated construction, the series of outlet valves 23 isconstructed integrally with the pumping membrane 17 and each outletvalve 23 comprises an op- I posed pair of lips 75 which are biased intoengagement 3 with each other and arranged solely to permit fluid outflowfrom the associated cavity 19 in response to a greater pressurecondition in the associated cavity than in the fluid outlet passage 43.

As can be seen from FIG. 1, the intake valve member 71 interfits ornests with the adjacent end of the pumping membrane 71 and is retainedin position by the valve retainer 51.

The inlet valve member 71 is made of resilient material and each inletvalve 21 comprises an opposed pair of lips 77 which extend into theadjacent end of the associated cavity 19 and which are biased towardclosed position and arranged solely to permit fluid inflow into theassociated cavity from the inlet passage 55 in response to a pressurecondition in the cavity less than in the inlet passage 55.

In the illustrated construction, the means for squeezing the pumpingmembrane 17 to periodically reduce the volume of the cavities 19 andpermitting expansion of the cavities to induce flow therethroughcomprises a drive shaft 81 which extends centrally through the housing13 and is supported by suitable bearings 83 and 85. Excentricallymounted on the shaft 81 interiorly of the housing 13 and for commonrotation therewith is a generally cylindrical cam element 87 having anouter surface engaging a bearing assembly 89. In turn, the bearingassembly 89 is in engagement with the inner surface of a rigid hollowcylindrical member 91 having an outer surface bonded to the cylindricalportion 61 of the pumping membrane 17. As a consequence, rotation of thedrive shaft 81 causes rotating oscilation and consequent deformation ofthe pumping membrane 17 to press or squeeze the cavities 19 in thepockets 15 on one side of the housing 13 to thereby expell fluid fromthe squeezed cavities, while the diametrically opposite cavities arepermitted to resiliently expand within the pockets 15 on the oppositeside of the housing and thereby to induce inflow of fluid into theexpanding cavities. 9

Various of the features of the invention are set forth in the followingclaims: v

1. A fluid pump comprising a hollow housing including means defining aseries of radially inwardly open, elongated pockets arranged in acircular array with the axis of said array being generally parallel withthe elongation of said pockets, a pumping membrane of resilient materialincluding a series of elongated pumping cavities respectively located insaidhousingvpockets, a series of one-way inlet valves respectivelyconnected with said pumping cavities, a series of one-way outlet valvesrespectively connected with said pumping cavities, rotary means locatedwithin said housing in excentric relation to said array of pockets forperiodically squeezing said membrane within said pockets to reduce thevolume of said cavities and thereafter-permitting resilient expansion ofsaid cavities within said pockets so as thereby to induce fluid outflowfrom said cavities through said outlet valves in response to squeezingof said membrane and to induce fluid inflow into said cavities throughsaid inlet valves in response to said resilient expansion of saidcavities.

2. A fluid pump in accordance with claim 1 wherein said rotary meanscomprises a drive shaft extending through said housing in concentricrelation to said array of pockets, a cylindrical cam element mounted onsaid drive shaft in excentric relation thereto and for common rotationtherewith and including an outer surface, a bearing engaged with saidouter surface of said cam element, and a hollow cylindrical memberincluding an outer surface bonded to said membrane and an inner surfacein engagement with saidbearing.

3. A fluid pump in accordance withclaim 1 wherein one of said series ofinlet valves and said series of outlet valves is formed in a commonmember located at one end of said membrane and including a fluid passagecommunicating with said one seriesof valves.

4. A fluid pump in accordance with claim 1 wherein one of said series ofinlet valves and said series of outlet valves is formed integrally withsaid membrane adjacent to one end thereof and communicates with a com-

1. A fluid pump comprising a hollow housing including means defining aseries of radially inwardly open, elongated pockets arranged in acircular array with the axis of said array being generally paRallel withthe elongation of said pockets, a pumping membrane of resilient materialincluding a series of elongated pumping cavities respectively located insaid housing pockets, a series of one-way inlet valves respectivelyconnected with said pumping cavities, a series of one-way outlet valvesrespectively connected with said pumping cavities, rotary means locatedwithin said housing in excentric relation to said array of pockets forperiodically squeezing said membrane within said pockets to reduce thevolume of said cavities and thereafter permitting resilient expansion ofsaid cavities within said pockets so as thereby to induce fluid outflowfrom said cavities through said outlet valves in response to squeezingof said membrane and to induce fluid inflow into said cavities throughsaid inlet valves in response to said resilient expansion of saidcavities.
 2. A fluid pump in accordance with claim 1 wherein said rotarymeans comprises a drive shaft extending through said housing inconcentric relation to said array of pockets, a cylindrical cam elementmounted on said drive shaft in excentric relation thereto and for commonrotation therewith and including an outer surface, a bearing engagedwith said outer surface of said cam element, and a hollow cylindricalmember including an outer surface bonded to said membrane and an innersurface in engagement with said bearing.
 3. A fluid pump in accordancewith claim 1 wherein one of said series of inlet valves and said seriesof outlet valves is formed in a common member located at one end of saidmembrane and including a fluid passage communicating with said oneseries of valves.
 4. A fluid pump in accordance with claim 1 wherein oneof said series of inlet valves and said series of outlet valves isformed integrally with said membrane adjacent to one end thereof andcommunicates with a common fluid passage.